TWI688791B - Head-mounted display device - Google Patents

Abstract

A head-mounted display device including a body, a display element, and two lens groups is provided. The display element is disposed on the body and is adapted to provide an image beam. The two lens groups are disposed on the transmission path of the image beam. Each lens group includes a plurality of lenses, wherein one of the lenses has an astigmatism surface on at least one side of the display element. The astigmatism surface is non-rotationally symmetrical, and the image beam has astigmatic aberration after passing through the astigmatism surface.

Description

Head-mounted display device

The invention relates to an electronic device, and in particular to a head-mounted display device.

With the development of the technology industry, the types, functions, and methods of electronic devices are becoming more and more diversified. Wearable electronic devices that can be worn directly on the user's body are also born. There are quite a few types of head-mounted electronic devices. Take head-mounted electronic devices such as blindfolds for example. After wearing such electronic devices, users can see the stereoscopic image in addition to the stereoscopic image. The part rotates and changes to provide users with a more immersive experience.

However, the images provided by such head-mounted electronic devices are likely to produce a screen door effect due to the structure of the display element, which seriously affects the user's immersion during use. Therefore, how to reduce the screen-window effect generated by the head-mounted electronic device is a matter for those skilled in the art to study.

The invention provides a head-mounted display device, which can reduce the screen window effect generated by the head-mounted electronic device.

The invention provides a head-mounted display device including a body, a display element and two lens groups. The display element is disposed on the body and is suitable for providing an image beam. The two lens groups are arranged on the transmission path of the image beam. Each lens group includes a plurality of lenses, wherein one of the lenses has a light scattering surface on at least one side of the display element. The astigmatism surface is non-rotationally symmetric, and the image beam has astigmatic aberration after passing through the astigmatism surface.

In an embodiment of the present invention, the image beam transmitted through one part of the astigmatic plane is different from the image focal plane passed through the other part of the astigmatic plane.

In an embodiment of the present invention, the curvature of the above-mentioned astigmatism plane on a plane parallel to a plane formed by an X direction and a Z direction is different from a curvature of a plane formed parallel to a Y direction and a Z direction Curvature of the cut line on the plane. The X direction, Y direction, and Z direction are perpendicular to each other, and the image beam is transmitted in a direction parallel to the Z direction.

In an embodiment of the invention, the above-mentioned astigmatism surface is a curved surface.

In an embodiment of the invention, the above-mentioned lens having a light-scattering surface has a refractive power.

In an embodiment of the invention, the above-mentioned lens with a light-scattering surface has a Fresnel surface on the side adjacent to the display element.

In an embodiment of the invention, one of the above-mentioned lenses has a Fresnel surface on the side adjacent to the display element.

In an embodiment of the invention, the above-mentioned display element includes a plurality of display pixels arranged in an array and a plurality of light-shielding regions for separating the display pixels.

In an embodiment of the invention, the lens with a light-scattering surface is a liquid crystal lens.

In an embodiment of the present invention, the above lens with a light-scattering surface includes a liquid crystal layer and two electrode structures respectively regulating the different axial directions of the liquid crystal layer, and the curvature of the cross-sectional line of the light-scattering surface in two directions perpendicular to each other is respectively composed of two electrodes The structure is modulated by liquid crystal layer.

In an embodiment of the present invention, the lens with the astigmatism surface is a liquid lens.

In an embodiment of the present invention, the lens having a light-generating surface is composed of a liquid and a polymer film. The lens is suitable for changing shape by liquid and polymer film.

In an embodiment of the invention, the lens with a light-scattering surface includes a control element and at least one electrode. The control element is connected to the lens via at least one electrode. The control element controls the lens with at least one electrode according to the screen displayed by the display element to generate a light scattering surface.

In an embodiment of the invention, the above-mentioned head-mounted display device further includes a sensor adapted to sense an eyeball movement. The control element controls the lens according to the movement of the eyeball sensed by the sensor.

In an embodiment of the invention, the lens is composed of multifocal lenses.

In an embodiment of the invention, the astigmatism surface of the lens has a plurality of different astigmatism areas.

In an embodiment of the present invention, the lens with the astigmatism generating surface can be rotated, moved or tilted relative to the display element.

In an embodiment of the invention, the above-mentioned head-mounted display device further includes a sensor and a control element. The sensor is suitable for sensing the movement of an eyeball. The control element controls the lens having the astigmatism surface according to the movement of the eyeball sensed by the sensor.

Based on the above, in the head-mounted display device of the present invention, one of the lenses of the lens group has a light-scattering surface on the side away from the display element. The astigmatism surface is non-rotationally symmetrical, and allows the image beam to pass through with astigmatic aberrations. Therefore, the shading area in the display element cannot be imaged in the human eye, thereby reducing the screen window effect generated by the shading area when the human eye observes the image provided by the head-mounted display device.

In order to make the above-mentioned features and advantages of the present invention more obvious and understandable, the embodiments are specifically described below in conjunction with the accompanying drawings for detailed description as follows.

FIG. 1 is a schematic perspective view of a head-mounted display device according to an embodiment of the invention. An embodiment of the present invention provides a head-mounted display device 100 that allows a user to wear and achieve the effect of experiencing virtual reality, augmented reality, or mixed reality. In this embodiment, the head-mounted display device 100 includes a body 110, a display element 120, two lens groups 130, and a wearer 140. In other embodiments, the type and quantity of each component can be adjusted according to needs or application scenarios, and the invention is not limited thereto.

In this embodiment, the head-mounted display device 100 includes a body 110, a display element 120 and two lens groups 130. The body 110 is, for example, a combination of a housing and an optical system. The optical system is mounted in the housing. The optical system is composed of a display element 120 and two lens groups 130, for example. In this embodiment, the body 110 includes a wearer 112 suitable for being worn on the user's head, but the invention is not limited to this. The display element 120 may be a built-in display device or an external portable display device (such as a smart phone, etc.), and the invention is not limited thereto.

FIG. 2 is a schematic diagram of a partial display surface of the display element of FIG. 1. Please refer to Figure 1 and Figure 2. The display element 120 is disposed on the body 110 and is suitable for providing an image beam L. The type of the display element 120 can be adjusted according to the application of the head-mounted display device 100 in a virtual reality system (augmented reality system), an augmented reality system (augmented reality system) or a mixed reality system (mixed reality system) . The optical system includes two lens groups 130 and other optical elements used to change the optical path of the display element 120, such as lenses, light guides, prisms, etc. The present invention is not limited thereto. In this embodiment, the display element 120 includes a plurality of display pixels 122 arranged in an array and a plurality of light-shielding regions 124 for separating the display pixels 122.

The two lens groups 130 are arranged on the transmission path of the image light beam L. Each lens group 130 includes a plurality of lenses, wherein at least one of the lenses has a light scattering surface on a side away from the display element 120, wherein at least one of the lenses has a Fresnel surface on the side adjacent to the display element 120 .

FIG. 3 is a schematic side view of part of the lens group of FIG. 1 in the YZ plane. 4 is a schematic side view of part of the lens group in FIG. 1 in the XZ plane. FIG. 5 is a schematic side view of FIG. 3 and FIG. 4 superimposed. Please refer to Figure 1, Figure 3 to Figure 5. For example, in this embodiment, each lens group 130 includes a lens 132 having a refractive power, and in this lens 132, the side away from the display element 120 is a light scattering surface SA, and a side adjacent to the display element 120 The side is the Fresnel surface SF. In other words, in this embodiment, the lens 132 has both the light scattering surface SA and the Fresnel surface SF, but the invention is not limited thereto. In some embodiments, the light scattering surface SA and the Fresnel surface SF can also be configured on different lenses. For example, in this embodiment, the Fresnel surface SF and the light scattering surface SA are the light incident surface and the light emitting surface of the lens 132, respectively.

The astigmatism surface SA is non-rotationally symmetrical and curved, and is configured as a light exit surface, so that the image light beam L passes through the astigmatism surface SA and has astigmatism. In detail, the curvature of the cross-section of the astigmatism plane SA on a plane parallel to the plane formed by the X direction and the Z direction (as shown in the FIG. 3 as the astigmatism plane SA_XZ) is different from that parallel to the Y direction and the Z direction The curvature of the cut line on a plane of the formed plane (astigmatism plane SA_YZ shown in FIG. 4) is the difference in curvature shown in FIG. 5. For example, the astigmatic surface SA is, for example, an ellipsoid surface. The X direction, the Y direction and the Z direction are perpendicular to each other, and the image beam L (as shown in FIG. 1) is transmitted in a direction parallel to the Z direction.

Therefore, after the image beam L passes through the astigmatic surface SA, astigmatic aberration occurs due to the asymmetrical characteristics of the astigmatic surface SA, which can slightly blur the image viewed by the user, thereby reducing the shading area 124 in the display element 120 (see Figure 2) The imaging effect in human eyes. In other words, the imaging of the shading area 124 in the display device 120 can be slightly blurred by the astigmatism effect of the above image and cannot be imaged in the human eye. In this way, the screen effect of the image provided by the human head-mounted display device 100 due to the shading area 124 can be reduced.

On the other hand, the Fresnel surface SF is rotationally symmetric and is configured as a light incident surface, which can save the volume of the overall lens group 130. The Fresnel surface SF can be arranged in the lens 132 having the light-scattering surface SA. However, in other embodiments, the Fresnel surface SF can also be configured in other lenses, and the invention is not limited thereto.

6 is a schematic diagram of the optical path of some lens groups in the YZ plane according to another embodiment. 7 is a schematic diagram of the optical path of some lens groups in FIG. 6 in the XZ plane. FIG. 8 is a schematic diagram of a stereoscopic light path of part of the lens group in FIG. 6. Please refer to Figure 1, Figure 6 to Figure 8. The lens 132A illustrated in this embodiment can be applied to at least the two lens groups 130 illustrated in the embodiment of FIG. 1 described above, so the following description will be applied to the two lens groups 130 illustrated in the embodiment of FIG. 1, but the present invention Not limited to this. In this embodiment, after the image light beam L provided by the display element 120 passes through the diffusing surface SA, the curvature of the tangent line of the diffracting surface SA on a plane parallel to the plane formed by the X direction and the Z direction is different from that of the parallel The curvature of the cut line on a plane formed by the Y direction and the Z direction, so the image beam L is transmitted through the imaging focal plane of one part of the astigmatism plane SA and the imaging of the other part passed through the astigmatism plane SA The focal plane is different.

Specifically, in this embodiment, the curvature of the diffusive surface SA on a plane parallel to the plane formed by the Y direction and the Z direction is larger than the cross section of a plane parallel to the plane formed by the X direction and the Z direction Line curvature. Therefore, after the image beam L passes through the astigmatism plane SA, the focal length of the focal point F1 formed by the partial image beam L1 parallel to the Y direction at the imaging focal plane E1 will be greater than the partial image beam L2 parallel to the X direction at the imaging focus The focal length of the focal point F2 formed by the plane E2 is shown in FIGS. 6 to 8. In this way, after the image beam L passes through the astigmatic surface SA, astigmatic aberration is generated due to the asymmetrical characteristics of the astigmatic surface SA, so that the shading area 124 in the display element 120 cannot be imaged in the human eye, thereby reducing the human eye observation headwear The screen provided by the display device 100 is caused by the screen effect of the shading area 124.

In some embodiments, the lens with a light-scattering surface may be a liquid crystal lens. In detail, a lens with a light-scattering surface includes a liquid crystal layer and two electrode structures respectively regulating different axial directions of the liquid crystal layer. Therefore, the modulation of the two-electrode structure can be manipulated so that the liquid crystal material in the liquid crystal layer has different refractive indexes in different directions, thereby generating different equivalent cross-sectional curvatures in two directions perpendicular to each other. In this way, when the image beam passes through the astigmatic surface, astigmatic aberration will be generated due to the asymmetrical characteristics of the astigmatic surface, so that the shading area of the display element cannot be imaged in the human eye, thereby reducing human eye observation of the head-mounted display The screen provided by the device is due to the screen effect produced by the shading area.

Furthermore, in some embodiments, the lens with the light-scattering surface may be a liquid lens. The liquid lens is composed of, for example, a liquid and a polymer film covering the liquid. The liquid lens is suitable for changing the shape by controlling the liquid and the polymer film. In detail, the liquid lens includes a control element and at least one electrode, and the control element is connected to the liquid lens through at least one electrode. In an embodiment, the control element may control the liquid lens with at least one electrode according to the image displayed by the display element, thereby generating a light-scattering surface. In another embodiment, the head-mounted display device may further include a sensor for sensing a user's eye movement state. The control element can control the liquid lens according to the movement state of the eyeball sensed by the sensor. In other words, in this embodiment, the astigmatism surface produced by the liquid lens can be adjusted slightly and optimally with the movement of the human eye to achieve the best effect. In this way, the user can have a better visual experience.

In addition, in some embodiments, the lens having a light-scattering surface may be a multifocal lens. Therefore, the formed astigmatism surface can form a plurality of astigmatism surfaces with different optical conditions in a plurality of different areas on the multifocal lens. In other words, the astigmatism surface on the multifocal lens is composed of different astigmatism areas, and the optical conditions of these astigmatism areas are different from each other. Therefore, in this embodiment, the astigmatism surface generated by the multifocal lens can adaptively use the best-effect astigmatism area as the human eye moves. In this way, the user can have a better visual experience.

In addition, in all the embodiments described above, the lens with the light-scattering surface can be further rotated, moved, or tilted relative to the display element. For example, the head-mounted display device may further include a sensor and a control element, the sensor is adapted to sense a movement of the eyeball of the user, and the control element is based on the movement state of the eyeball sensed by the sensor Instead, control the lens with the astigmatism surface. Therefore, when the user experiences the head-mounted display device, the astigmatic surface can adaptively slightly adjust the position or angle of the astigmatic surface to the optimal position or angle with the movement of the human eye. In this way, the user can have a better visual experience.

In summary, in the head-mounted display device of the present invention, one of the lenses of the lens group has a light-scattering surface on the side away from the display element. The astigmatism surface is non-rotationally symmetrical, and allows the image beam to pass through with astigmatic aberrations. Therefore, the shading area in the display element cannot be imaged in the human eye, thereby reducing the screen window effect generated by the shading area when the human eye observes the image provided by the head-mounted display device.

Although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

100: Head-mounted display device 110: Ontology 112: Wearables 120: display element 122: display pixels 124: shading area 130: lens group 132, 132A: lens E1, E2: focal plane F1, F2: focus L, L1, L2: image beam SA, SA_XZ, SA_YZ: astigmatism surface SF: Fresnel surface

FIG. 1 is a schematic perspective view of a head-mounted display device according to an embodiment of the invention. FIG. 2 is a schematic diagram of a partial display surface of the display element of FIG. 1. FIG. 3 is a schematic side view of part of the lens group of FIG. 1 in the YZ plane. 4 is a schematic side view of part of the lens group in FIG. 1 in the XZ plane. FIG. 5 is a schematic side view of FIG. 3 and FIG. 4 superimposed. 6 is a schematic diagram of the optical path of some lens groups in the YZ plane according to another embodiment. 7 is a schematic diagram of the optical path of some lens groups in FIG. 6 in the XZ plane. FIG. 8 is a schematic diagram of a stereoscopic light path of part of the lens group in FIG. 6.

100: Head-mounted display device

110: Ontology

112: Wearables

120: display element

130: lens group

L: Image beam

Claims (18)

A head-mounted display device, including: An ontology A display element, disposed on the body, suitable for providing an image beam; and Two lens groups are arranged on the transmission path of the image beam, and each lens group includes a plurality of lenses, wherein one of the lenses has a light scattering surface on at least one side of the display element, and the light scattering surface is non-rotating Symmetrical, and the image beam has astigmatic aberration after passing through the astigmatic surface. The head-mounted display device as described in item 1 of the scope of the patent application, wherein the image beam passes through the imaging focal plane of one part of the astigmatic plane and the imaging focal plane passes through the other part of the astigmatic plane different. The head-mounted display device as described in item 1 of the patent application scope, wherein the curvature of the ray interception plane on a plane parallel to the plane formed by an X direction and a Z direction is different from that of the plane parallel to a Y direction and The curvature of the tangent line on a plane formed by the Z direction, the X direction, the Y direction and the Z direction are perpendicular to each other, and the image beam is transmitted in a direction parallel to the Z direction. The head-mounted display device as described in item 1 of the patent application, wherein the light-diffusing surface is a curved surface. The head-mounted display device as described in item 1 of the patent application range, wherein the lens having the astigmatic surface has a refractive power. The head-mounted display device as described in item 1 of the patent application range, wherein the lens having the light-scattering surface has a Fresnel surface on the side adjacent to the display element. The head-mounted display device as described in item 1 of the patent application range, wherein the other one of the lenses has a Fresnel surface on the side adjacent to the display element. The head-mounted display device as described in item 1 of the patent application scope, wherein the display element includes a plurality of display pixels arranged in an array and a plurality of light-shielding regions for separating the display pixels. The head-mounted display device as described in item 1 of the patent application range, wherein the lens having the light-scattering surface is a liquid crystal lens. The head-mounted display device as described in item 9 of the patent application scope, wherein the lens with the light-scattering surface includes a liquid crystal layer and two electrode structures respectively regulating the different axial directions of the liquid crystal layer, and the light-scattering surface is perpendicular to each other The curvature of the intercept line in the direction is formed by modulating the liquid crystal layer by the two-electrode structure. The head-mounted display device as described in item 1 of the scope of the patent application, wherein the lens having the astigmatic surface is a liquid lens. The head-mounted display device as described in item 11 of the patent application range, wherein the lens having the light-generating surface is composed of a liquid and a polymer film, and the lens is suitable for controlling the liquid and the polymer film Change shape. The head-mounted display device as claimed in item 11 of the patent application range, wherein the lens with the light scattering surface includes a control element and at least one electrode, the control element is connected to the lens via the at least one electrode, and the control element is based on the The screen displayed by the display device controls the lens with the at least one electrode to generate the light-scattering surface. The head-mounted display device as described in item 13 of the patent application scope further includes a sensor adapted to sense a movement of the eyeball, and the control element controls the lens according to the movement of the eyeball sensed by the sensor . The head-mounted display device as described in item 1 of the patent application range, wherein the lens having the light-scattering surface is a multifocal lens. The head-mounted display device as described in item 15 of the patent application range, wherein the light-diffusing surface of the lens has a plurality of different light-diffusing areas. The head-mounted display device as described in item 1 of the patent application range, wherein the lens having the light-generating surface can be rotated, moved, or tilted relative to the display element. The head-mounted display device as described in item 17 of the patent application scope further includes a sensor and a control element, the sensor is adapted to sense an eye movement, and the control element is sensed by the sensor The movement of the eyeball controls the lens having the astigmatism surface.

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